Track-roadbed and method of forming the same



s. G. HOWE. I TRACK ROADBED AND METHOD OF FORMING THE SAME.

APPLICATION FILED IAN-24.192]- Patented Oct. 4, 1921..

v-oantoz S0207? CLJMw-e W WWW UNITED STATES PATENT OFFICE.

SOLON G. HOWE, OF DETROIT, MICHIGAN, ASSIGNOR OF ONE-HALF T0 WILIB UR BROTHERTON, OF DETROIT, MICHIGAN'.

TRACK-ItOADBED AND METHOD OF FORMING THE SAME.

Specification of Letters Patent.

Patented Oct. 4., 1921.

Application filed January 24, 1921. Serial No. 439,493.

To all whom it may concern:

Be it known that I, SoLoN G. Hows, a

citizen of the United States of America,

residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Track- Roadbeds and Methods of Forming the same, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to rail track beds, more particularly designed for use on city streets and country roads which are'used for traflic of other vehicles than the railway cars. It is the object of the invention; first, toobtain a satisfactory-durable supporting bed for the rails; and second, a surface which is suitable for other vehicular traffic.

In the drawings:

Figure 1 is a sectional perspective view showing my improvedconstruction showing a double track road; I

Fig. 2 is a cross-section of the single track road.

In the construction of railway road beds it is customary to use broken stone both for the sub-bed and for ballasting material, but such material alone does not form a satisfactory road surface for other traffic. Furthermore, the ready passage of water through the open stone'will find access to the sub-soil and the softening of this sub soil by such moisture will cause the loss-of support in certain places, destroying the level of the track. NVhere the voids between the stone particles are filled with finer mate rial, this lessens thepeneration of moisture, but wherethis void filler contains aclay binder, it becomes slimy when wet and acts as a lubricant, permitting the displacement of the larger particles under load. On the other hand, if the void filler has no binder, it will soon work out, leaving only the open stone.

With my improved construction the tracks are supported by a broken stone base and the voids are filled with finer material, free from any clay and maintained in place by a moisture binder, due to the incorporaton therein of a deliquescent salt. The surface of the road may thus be maintained in a level packed condition suitable for the traflic of the ordinary vehicles, while the tracks are properly supported and the sub-soil base is protected from moisture to avoid softening of the same.

In detail,-my method of constructing the road bed is as follows: Thesub-grade for the road bed is first prepared and a trench is placed thereon for receiving the'dr'ainage water. In this trench Av are laid tiles B, preferably about a quarter of an inch apart with a crevice at the top of the tile covered by tarred paper, or other material for preventing the filling of the tile with fine material. The trench is then filled with coarse material such as stone, slag, screenings or sand and atsuitable intervals tiles are connected with outlets to the sewer or catch basin, if on city streets, or to the sewers or 'drainage'ditches on country roads. The subgrade C is preferably slightly sloped toward the ditch A and this ditch :is preferably placed at the center so as to receive the drainage from both sides. I 7

-Above the sub-grade is placed a layer of coarse broken stone, preferably from one to three inches in size, and having the voids filled with a fine material (dust to inch in size). This material before depositing on the subgrade is preferably passed through a mechanical mixer and a saturated deliquescent salt is added, preferably in the proportion ofabout one-half gallon of the liquid containing one part chemical to three of water to each cubic foot of the body. When this material is once mixed, the moisture maintained in the void filler will prevent the same from shaking out during transit or in handling.

Before depositing this mixed material upon the sub-grade, the latter is rolled and compacted solidly, the soft spots in the same found with a steel prod being filled with some of the base material and tamped until as solid as the rest of the base. The sub-base is then covered with the mixed base material to a depth preferably of about six inches and is packed by rolling with a heavy roller. The ties are then placed in position and spaced, the rails laid and spiked to the ties and the structure is then jacked up to bring the top of the rails to the street level. When in this position, there should be from 11} to 2 inches between the ties and the packed bed.

To complete the road, a finer void-filled chemically treated road material is placed "rails, and finally filled up to the level of the surface of the rails. This will produce a smooth even and hard surface on a level with the track, whichis well adapted for other vehicles. The flanges of the track wheels will out their own groove and there is not suflicient resistance in material to in any way endanger the derailing of the car.

A road formed as above described has practically the same advantages as a concrete surface, while at the same time not interfering with'the repair of the tracks or. the reballasting of the same. The void filler being impregnated with the deliques-' cent salt, will at all times retain moisture which will act as a binder and also will prevent the formation of dust. Thu the construction is particularly adapted for unpaved city streets and for country roads, Which are also used for interurban track. I

To prevent the breaking away of the road outside of the tracks, I preferably employ a curb whichis placed outside of the ties, but preferably rests upon the base layer.

This curb D willvform a solid abutment. against which the void-filled road material is tamped and will hold the same from. beingforced outward or otherwise displaced to produce a road. Another function performed by this curb is a separation between the void-filled road material' and the pavement where the street is paved. Thus it is possible to have a paved road between the outer curb and the curb adjacent to the track, while the space between the tracks is filled with the loose material, which at any time may be dug up in case there is necessity for repairs.

What I claim as my invention is: i

1. The combination with a railway track, of a supporting bed-therefor-formedof a void-filled coarse road material impregnated with a'deliquescent salt, and a ballasting of finer road material of the same character, the latter material forming a hard smooth surface for other vehicular traflic.

*2. The combination with a railwaytrack,

of a supporting'base therefor formed of coarse voidfilled road material impregnated with a deliquescent salt, and a ballasting of finer material of'the same character, the latter filling the spaces between the ties and tracks and forming a hard smooth surface for other vehicular traffic, and means for'draining off the water which percolates through such material to avoid softening the sub-soil base.

3. A combined rail and roadway comprising a sub-grade base, a drainage trench in said base having outlets at intervals, filtering material-filling said trench, a base of coarse void-filled road material impregnated with-deliquescent salt coveringsaid sub-grade base, ties and rails above said road material base and finer void-filled road material impregnated with a deliquescent salt covering said base, filling the spaces between said ties and rails, and forming a wearing surface substantially on the level of the top of the rails. 7

4E. The method of forming a combined.

rail and roadway comprising first'forming a sub-grade base, filling of all soft places in said base with road material, forming a drainage trench in said sub-grade base, laying a tile drain in said trench having outlets at intervals, filling said trench with a porous material, placing a layer of coarse void-filled road material impregnated with a deliquescent salt over said sub-gradebase,

laying theties and tracks above said base, 'ballasting the tracks with finer void-filled road material impregnated-with a deliquescent salt, and filling in the spaces between the ties and tracks with the same material to form a wearing surface substantially on the level with the tops of the rails.

5. The combination with a railway track, of a supporting bed therefor formed of void-filled coarsematerial impregnated with a deliquescent salt, a curbing laid parallel to the track on the outer side thereof, and a ballasting of finer void-filled and impregnated road material filling the spaces between the tracks and extending to said curb.

6. The combination with a railway track, of a supporting bed therefor formed of void-filled coarse road material impregnated with a deliquescent salt, a curb laid upon said bed outside of the track and extending to the level of the upper surfaceof the rails, and a ballasting of finer void-filled and impregnated road material filling the space between tracks and extending to said curb.

In testimony whereof I afiix my signature. 

